<!DOCTYPE html>
<html lang="en" xmlns:v-on="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>created</title>
    <script src="https://cdn.jsdelivr.net/npm/vue@2.6.12"></script>
</head>
<body>
    <div id="app">
        <input type="text" v-model="num">
        <div>{{num}}</div>
        <div v-model="value">{{value}}</div>
        <msg>{{msg}}</msg>

    </div>
    <script>
        var app=new Vue({
            el:"#app",
            data:{
                value:0,
                num:0,
                msg:"hello"

            },
            created(){
                this.msg="Goodbye vue"
            }
            
        })
    </script>
</body>
</html>